The areas of long-fallow lands have increased noteworthily during the last two decades. Processes of indigenous steppes rehabilitation are accompanied by changes in biotic components. Complexes of soil invertebrates are the most responsive when removing the anthropogenic load. The dynamics of the structural and quantitative characteristics of the soil biota demonstrates the dependence of the rehabilitation processes on the features of the hydrothermal regime. With each new stage of regeneration of phytocenoses, the taxonomic diversity grows, the average number and biomass increase, and the soil mesopopulation becomes more resistant to the impact of external factors.